A 70 year old man was admitted with signs of severe right heart failure 10 months following a mitral valve repair (quadrangular resection and Carpentier ring insertion). Examination revealed a soft systolic murmur and extensive peripheral oedema which responded initially to high doses of furosemide and spironolactone. Transoesophageal echocardiography demonstrated only mild mitral regurgitation and good left ventricular function. Surprisingly there were two defects in the intra-atrial septum (panel A) which had not been present at two previous transoesophageal echocardiograms. At cardiac catheterisation, the left to right shunt was calculated at 1.7:1; however, this was likely to be an underestimation as there was also found to be diastolic equalisation of pressures suggesting pericardial constriction (panel B). It was uncertain whether the left to right shunt or the cardiac constriction was the most likely cause of the patient’s symptoms.

The patient initially underwent successful percutaneous closure of the defect in the intra-atrial septum with an Amplatzer Cribiform occluder (panels C, D). It had been the intension to then send the patient for surgical pericardectomy; however, after closure of the atrial defect the patient made a dramatic recovery, presumably due to reduction in the size of the right ventricle and relative relief of the constriction.

The aetiology of the acquired defect in the atrial septum is uncertain but may have been caused by stretch of an existing patent foramen ovale or atrial septal defect, although surgical trauma at the time of mitral valve repair cannot be excluded.